Hollow concrete core form



June 19, 1956 KRIEG HOLLOW CONCRETE CORE FORM 2 Sheets-Sheet 1 FiledMarch 5, 1952 INVENTOR. .Ed Wa rd Krie V2" June 19, KRIEG HOLLOWCONCRETE CORE FORM 2 Sheets-Sheet 2 Filed March a, 1952 INVENTOR. .E'dWard Krie BY United States Patent HOLLOW CONCRETE CORE FORM EdwardKrieg, Corvallis, Greg.

Application March 3, 1952, Serial No. 274,543

4 (Jlaims. (Cl. -131) My invention relates to a form or mold used in theconstruction of a hollow concrete wall and, more particularly, to acenter form which is inexpensive to a degree that disposition thereofafter a single use is practical and, economically, is sound. By way ofexample, such a form may be made integral with and left embedded withinthe center of a finished concrete wall.

Increasing labor, lumber and steel costs today are turning the attentionof many contractors toward the feasibility of constructing homes andsmall commercial buildings either (1) with concrete blocks or (2)on-the-job poured hollow concrete walls. Of these two constructions,precast concrete blocks heretofore have been more economical. This hascaused many contractors to shy away from the poured hollow wallconstruction in spite of the fact that more strength can be gained bythe latter. Further, block walls are easier to construct in that lessskill is required and fewer man hours are consumed in comparison to apoured hollow wall of similar dimensions. This latter advantage is bornof the fact that hollow wall construction heretofore has been practicalonly when rather expensive and complex molds or forms are employed toform the core of the hollow wall. Thus, the typical mold or center formfor a hollow wall is made of metal, such as stainless steel, and iscollapsible so the mold may be withdrawn after the concrete takes aninitial set. Many patentees have turned their inventive efforts towardthe improvement of these collapsible metal forms. In summary, however, Ihave found that all of these metal forms are expensive and are complexin use to a degree which renders their use impractical for any but thelargest contractors or for use in any but large housing projects andbuildings.

Accordingly, a primary object of my invention is to provide a novel andimproved mold or center form for the construction of a hollow concretewall, said center form to be inexpensive, practical, and easy to use andto be disposable in the sense that the wall can be poured about the formand the form then can be left in place permanently. Such a form, it willbe evident, eliminates the need for manipulability in the parts thereofso that less skilled labor may be employed and the construction ofstructurally superior poured walls once more can compete with blockwalls.

In general, both a precast concrete block wall and a .hollow pouredconcrete wall are designed to provide a central dead air space. Such aspace serves to insulate against heat loss, to trap moisture, to deadenthe transmission of sound, and to provide an inexpensive quickconstruction technique of universal appeal. At the same time, it isevident that both the block and the poured type of wall must possesssufiicient structural strength to support the floor loads and/ orlateral earth or wind pressures which will be imposed thereon. With ablock wall, of course, lateral tie wires and vertical reinforcing rodsare vdifficult to place and most walls constructed therefrom depend fortheir stability and strength upon the dead weight of the blocks. Thisdependence dictates the use "ice of a relatively large and expensiveblock in most home construction. Further, block wall construction per seis not moisture impervious since the wall is continuous laterallythrough the ends of the blocks and through the mortar joints. These allare deficiencies or disadvantages which it is an object of my inventionto eliminate in the construction of a wall.

The poured hollow wall which heretofore has been in use also possessescertain inherent disadvantages. Thus, the complex and expensivecollapsible metal forms or molds heretofore used make difficult theplacing of reinforcing rods or tie wires since these elements must beretained yet the forms must be removed after the wall is poured.Similarly, it heretofore has been diflicult to achieve a continuoushollow core in the wall since the Wall is poured in vertically stackedhorizontal courses and the mold or center form in each course must restupon some support member provided either by the next lower course or bythe outer forms. A continuous hollow core, on the other hand, is themost efllcient type as concerns insulation, moisture trapping, and sounddeadening.

Having in mind the above disadvantages of prior hollow wall constructiontechniques, it is one object of my invention to provide a novel centerform which will define a continuous insulation core of uniform lateralwidth running centrally up through a hollow poured wall.

Another object of my invention is to provide, in that construction of ahollow concrete wall which proceeds in successive vertically stackedhorizontal courses, a center form or mold which will carry, adjacent thetop and bottom thereof, the respective mated halves of a two pieceintermeshing grip means frictionally for interconnecting the centerforms of adjoining horizontal courses. Thus, the wall may be poured inthe conventional horizontal courses yet the insulation core will becontinuous and of substantially uniform lateral width.

To define a poured hollow wall having the strength of a solid Wall, itis a further object of my invention to pierce the novel center form witha plurality of elongated tie wires which project beyond the sides of thecenter form so the opposite ends of the wires will be buried in theopposite halves of the finished hollow wall to tie these halvestogether.

Yet another object of my invention is to provide a novel spacer meansfor use with the tie wires above explained, said spacer means serving togrip the ends of the laterally projecting tie wires in order to maintainthe said lateral projection while the Wall is poured. In this manner, awall of uniform and unvaried strength, through course after course, canbe constructed.

In conjunction with the center form or mold above defined, it is anotherobject of my invention to provide three species of insulation means, anyone of which will occupy a majority of the hollow interior of the formand will abut the sides of the form both to maintain the lateral spacingof the sides during construction and to enhance the insulationproperties of the finished Wall.

In service of the above inventive objects, the center form of theinstant invention is positioned intermediate two spaced vertical outerforms which are adapted to be removed after the wall is finished. Incontrast with these outer forms, the center form is constructed of paperboard, cellulose fiber insulating board, or the like and is adapted toremain permanently embedded within the finished wall in definition ofthe core thereof. Thus, the center form per se defines a box-likestructure having a hollow interior which is occupied by an insulationmeans in the form of any one of the three species above mentioned.Further, a plurality of elongated tie wires extend laterally through thecenter form and project beyond the sides thereof. These tie wiresterminate short of the outer forms so the opposite ends thereof will beburied in the opposite halves o and of the finished hollow wall to tiethem together. Still further, the projecting ends of each tie wire aregripped by a spacer means which bears upon the outer face of thecorresponding center form side Wall to maintain the said lateralprojection of the tie wire ends during pouring and curing. Thus, theentire center form'assembly is inexpensive to fabricate and is simple touse. Additionally, the novel disposition of the tie Wires and insulationmeans strengthens the form during construction of the wall and ties thetwo halves of the wall together so the strength thereof is equal to thatof a solid wall, yet a continuous central insulation core is provided.

The above and other desirable objects, points of novelty, and advantagesinherent in and encompassed by :my in vention will become apparent fromthe ensuing description, taken in conjunction with the accompanyingdrawings, wherein;

l isa perspective view of a first species of my invention showing thecenter form in process of assembly with the intersecting andinterlocking partition strips thereof exposed to view;

Fig. 2 is another perspective view of the first species of my invention,this figure showing the center form completely assembled with the tiewires and spacer means projecting from the exposed face thereof;

Fig. 3 is a section view through a partially completed hollow concretewall with one horizontal course already poured and with the center formof the first species in place just prior to the pouring of a secondhorizontal course; 7

Fig. 4 is a foreshortened detail view, taken substantially on the line4-4 of Fig. 3, showing one of the twisted tie wires and the manner inwhich this Wire extends laterally through the center form and projectsbeyond the sides thereof;

Fig. 5 is a further detail view, taken substantially on the line 5-5 ofFig. 4, more particularly indicating the manner in which the ends of thetie wires are bent to project substantially parallel to the sides of thecenter fdrm'more efi'iciently to tie the halves of the hollow concretewall together;

Fig. 6 is a detail perspective of one of the spacer means tlziroughwhich theend of a tie wire is threaded and about which the end of thetie wire is bent in orderthat the lateral projection of the wire will bemaintained during pouring;

Fig. 7 is asecti'onal detail view, taken substantially on the line 7-'7of Fig. 1, showing one preferred construction material for the centerform, this material being a corrugated paper board having the outer facethereof coated with a water impervious substance such as asphalt;

Fig. 8 is a perspective view of a partially completed concrete wall inwhich the second species of my invention is disclosed, said secondspecies having a mass of loose grains of granular insulating materialconfined within'the hollow interior of the center form; and

Figs. 9 and lOillustrate the third species of my invention, Fig. 9showing a large rectangular block of fibrous insulating material orcellulose insulating board and Fig. 10, taken substantially on the line10-10 of Fig. 9;sho'v'v- 'ing'the fibrous nature of this material incrosssectional detail.

' Each of the three species of my invention is designed for assembly onthe job by a contractor. To this end a plurality'of elongatedrectangular sheets of non-metallic insulating material, such as thatshown at 11, are shipped in ap'ack'a'ge to the construction site. Eachsuch sheet is provided with two score lines 12 for folding purposes.Additionally, under separate package, a plurality of smaller rectangularsheets having longitudinal score lines may be provided. At the buildingsite, these latter sheets "are folded to define a channel shape as shownat 13 in Figs. 1 and'2. This channel shape defines an end wall adaptedto space the side walls which are formed from the larger sheet 11. Thus,when assembled, the sheet 11 and "the channel shape 13 will define ahollow rectangular box having an open or hollow interior as hereinafterwill be described.

It is in conjunction with the hollow interior of each box that the threespecies of my invention are used. Thus, each of these species defines aninsulation means which occupies a majority of the hollow interior andabuts the sides of the box to maintain the lateral spacing thereofduring pouring and curing of the wall. In Figs. 1, 2 and 3, thisinsulation means takes the form of a plurality of intermeshed andinterlocked strips 20 which bound and define a dead air space in thefinished wall. In Fig. 8, on the other hand, the second species of theinsulation means includes a mass of loose grains of granular insulatingmaterial 30 and, in Figs. 9 and 10, the insulation means is arectangular block of fibrous insulating material 40 of the type whichmay be used in making the form per se. Thus, each of the center formspecies provides a hollow envelope or rectangular box in which aninsulation means is retained. A typical, on-the-job assembly of one ofthese envelopes or boxes now will be described.

Referring to Figs. 1 and 2, the first species of the insulation means isformed from a plurality of elongated plane partition strips 21 whichintercept and interlock substantially at right angles one to another.Thus, they define an open egg-crate appearance and are arranged to lieperpendicular to and substantially centrally of onehalf of the sheet 11.To fix the partitions in place, depending tabs 22 may be provided andstaples 23 are driven therethr'ough. Thereafter, the channel shaped endpiece 13 may be assembled with one of the flanges 14 thereof in contactwith the sheet 11. Similar staples 23 can be utilized to secure thisflange to the sheet.

As a further step in the assembly of a center form, the sheet '11 isbent along the score lines 12 to assume the position shown in Fig. 2. Inthis position, the sheet defines two parallel rectangular side walls 15and an integral connecting top wall 16. Additionally, the other flange14 of the channel shape 13 is stapled, as at 23, to the abuttingsidewall so as to define a connecting end wall spacer for the hollowbox, the web 17 of the channel being arrangedperpendicular to the twoside walls.

As a final step in the assembly of each of the species, a plurality ofelongated twisted tie Wires 18 are provided. These tie wires are punchedlaterally through the hollow center form so as to pierce both thesidewalls thereof. Thereafter, each end of the wire is threaded throughan aperture 19d (see Fig. 6 in a spacer means 19. The 'sp'acer "then ismoved laterally against the outer face of the corresponding sidewall 15and the ends of the'vvire are bent about the protruding U-shaped bar 24to bind'the spacer andwire into an integral piece, the terminal ends ofeach wire being arranged substantially parallel'to the sidewalls 15 withan elongated straight portion 18a. In substance, the overall length ofeach spacer 1 9 and bar 24 is made equal to half the thickness of oneside ofthe w'all'for apurp'ose hereinafter to be described.

Before describing a typical construction technique utilizing thehollowcenter form above described, reference should be had to Fig. 7. Inthis figure, an enlarged cross-sectional detail of one of the side walls15 has been shown. Thus, I prefer to use one of two materials in formingthe hollow box. Both of these materials are inexpensive and can betermed a non-metallic insulating material, the first being a fibrouscellulose'insulating board such as shown at 40 in Figs. 9 and 10 andsuch'as is'sol'd "under the trade names Firtex or Cellotex. Thesecond'material is a corrugated paper board having one fiat face and onecorrugated face such as shown in Fig. 7. When wet, the insulating boardis somewhat stronger than thepaper board so the latter preferably istreated, ass-1'1- dicated at '2 5, with a coat of water imperviousmaterial suh as asphalt or a syiithetic i'esin. Selecting asphalt astypical, thecOatingZS is sprayed or wiped over the eerrugations oii'thatside of the paperboard which the wet concrete will contact. I have foundthat this disposition of the asphalt not only will make the paper boardwater impervious but will cause the asphalt to bond to the concreteafter the wall is formed. Thus, should the paper board itselfdisintegrate or rot away after a number of years, the Water imperviousasphalt layer will be retained in intimate contact with the inner facesof the hollow concerete wall.

During construction of a hollow concrete wall in vertically stackedhorizontal courses, two spaced vertical outer forms 26 (see Fig. 3)first are erected. If a previous lower horizontal course already hasbeen poured, the upper outer forms may be secured to the companion lowerforms with a nut and bolt assembly 27. In any event, these outer formsare adapted to be removed after the wall is erected and the hollowcenter form of the instant invention is arranged intermediate the twoouter forms. This arrangement makes evident another important feature ofmy invention. Thus, as shown in Figs. 1 and 2, the end channel shape 13terminates short of the lower margin of the side walls 15. Similarly,the partition strip 21 of the insulation means 20 also terminates shortof the lower margin of the side walls. This leaves the lower marginsfree to flex and, in generic language, it defines a grip means. Forexample, referring to Fig. 3, the lower margins 28 are straddling andcompressing the upper margins 29 of the next lower center form. Thisallows the upper center form to rest upon and to grip the lower form sothat successive courses of the hollow box will be positioned correctlywith respect to one another. I define these overlapping portions 28 and29 as the respective mated halves of a two-piece intermeshing grip meansfrictionally for interconnecting the center forms of adjoininghorizontal courses. Further, where desired, a wood spacer block 31 maybe interposed between the vertical outer forms 26 to hold the top of thecenter form in place during the pouring operation. Thus, I need not tiethe center form permanently to the outer forms 26 and am saving of metaland complex tying forms.

In Fig. 3, another important feature of my invention is illustrated. Astherein indicated, the tie wires 18 project laterally out from the sidewalls 15 a distance which substantially is equal to half the thicknessof one portion of the wall. That is to say, the tie wires 18 terminateshort of the outer forms 26 so the opposite ends thereof will be buriedin the opposite halves of the finished hollow wall to tie them togetheracross the center form. This tie-in, of course, is intended to produce ahollow wall having superior structural strength, yet one which ispossessed of a continuous insulation core running centrally up throughthe entire wall.

Once the various hollow center forms for a particular horizontal courseare in place, the wall is poured to a one course height. This pouring,as is evident in Fig. 3, progresses to the top of the outer forms 26 butleaves a portion of each center form projecting thereabove. Thisprojection is essential in order that the next higher center formfrictionally may grip the projecting portions and thus be retained inproper position intermediate the outer forms.

After the wall has been poured, the outer forms 26 are stripped away butthe center or inner forms are left in place permanently. This permanentembedding of the center forms in the finished wall is of littleconsequence cost-wise since the center forms preferably are formed ofpaper board or of an inexpensive cellulose fiber insulating board. Inany event, the labor cost of erecting a hollow wall with my novel centerform materially is reduced since the center forms do not have to becollapsed and stripped away. Still further, the overall strength of thefinished wall materially is enhanced because the tie wires 18 extendcompletely through the center form and tie together the respectivehalves of the wall.

Turning now to the species of my invention which is shown in Fig. 8, thehollow center form has beenturned on its side with the top wall 16 nowresting adjacent the next center form rather than adjacent the centerform in the higher or next lower horizontal course. At the same time,however, the lower margins 28 and the upper margins 29 of adjoininghorizontal courses are intermeshed and interlocked as with the previousspecies to define the respective mated halves of the two piece gripmeans. In essence then, the hollow center form of this species is thesame as the hollow center form of the previous species except that thepartition strips 21 are left out and an open top is provided. As shownin Fig. 8, the open top of the form is essential since the insulationmeans which occupies the hollow interior of this species is defined by amass of loose grains of granular insulating material 30. This insulatingmaterial is poured into the hollow interior of the center form from abucket or the like 32 after the center forms are assembled and in place.Thus, once again, the insulation value of the finished hollow wallmaterially is enhanced yet the cost of both the center form per se andthe labor for assembling the wall materially are reduced.

Referring lastly to Figs. 9 and 10, a hollow center form such as thatused with the previous species is illustrated. This form, however, doesnot have the tie wires 18 assembled therethrough prior to the time theinsulation means 40 is inserted in the hollow interior. Thus, theinsulation means 40 of this species consists of a large rectangularblock of fibrous insulating material or insulating board. Fig. 10illustrates the fibrous nature of this material and, as is known in theart, such a material is expensive yet is possessed of superiorinsulation qualities. In asembling the form of this third species, theblock of insulating material 40 first is positioned within the hollowinterior of the form and, thereafter, the tie wires 18 are assembledthrough the form. As is evident, the tie wires then will pierce boththe-block of insulating material and the walls of the form to tie theentire mass together in an integral unit. A plurality of these thirdspecies forms then may be assembled in horizontal courses with the tiewires in place.

In summation, I have provided a novel center form for use duringconstruction of a hollow concrete wall in vertically stacked horizontalcourses. This center form allows the definition of a continuousinsulation core which runs centrally up through the wall and the formitself may employ any one of three species of insulation means. Witheach species, the form is inexpensive to the end that it may be left inplace permanently embedded within the finished wall. Further, incombination with the insulation means, I have provided a plurality ofelongated tie wires which extend laterally through the center form andinsulation means and which protrude laterally beyond the side walls ofthe form. This protrusion terminates short of the outer forms in whichthe wall is poured so the opposite ends of the wires will be buried inthe opposite halves of the finished hollow wall to tie them together.Thus, a hollow concrete wall of superior struc tural strength and ofsuperior insulation qualities is provided at a minimal cost and with aslittle complexity of construction technique as is practical.

I claim:

1. In the construction of a hollow concrete wall, the combination of twospaced vertical outer forms adapted to be removed after the wall iserected and a hollow center form adapted to be made integral with and tobe embedded within the center of the finished wall, said center formbeing arranged intermediate the two outer forms and comprising; twolaterally spaced side sheets formed of non-metallic insulating materialand an end spacer means interconnecting said side sheets to define abox-like structure having a hollow interior, insulation means carriedwithin said hollow interior and abutting said side sheets to maintainthe lateral spacing thereof, and a plurality of elongated tie wiresextending laterally through said center forni, thefe'nfls of said tiewires pr'ojecting'beyon'd said side heets but terminating short of theouter forms to tie the Wall "together across the center form, at least ainortion of said center form being deformable and pro truding above saidouter forms to receive a removable spacer "for inter connecting saidouter and center forms durin'g'construct ion of said wall.

2. The combination of 'claiin '1 wherein said insulation means includesa plurality of elongated interlocking partitron Strips which intersectsubstantially at right angles and are arranged to lie perpendicular tothe plane of each side sheet. I

3. The combination of claim 1 wherein said insulation means inclu desamass of loose grains of granular insulating material confined Within thehollow interior of the "center form.

v 4. The 'cdmbinatio'nof claim 1 wherein said insulation means includesarectangular block ofrfibrous insulating material having the same generalsize and configuration as the hollow interior of the center form.

Re'fe'rences'Cite'd in the file of this patent UNITED STATES PATENTS1,193,542 Gregory Aug. 8, 1916 1,984,007 Babbitt Dec. 11, 1934 2,192,183Deut's'ch Mar. 5, 1940 2,344,749 Stevens Mar. 21', 1944 2,442,962Rllfiible June 8, 1948 2,460,848 Rover Feb. 8, 1949 2,645,929 Jones July21, 1953

